Can antioxidants be effective therapeutics?

Despite evidence that oxidative damage contributes to a wide range of clinically important pathologies, few antioxidants act as effective pharmaceuticals in vivo. The reasons for this therapeutic inefficacy include the challenge of targeting antioxidants to particular organs and intracellular locations, as well as the problem of matching the reactivity of antioxidants to the relevant damaging species in vivo. The difficulty of measuring antioxidant efficacy in vivo also makes the interpretation of results from clinical trials difficult. In this review, the challenges associated with antioxidant drug development are presented, and approaches to overcome these issues in order to design more effective therapeutic antioxidants are discussed.